Chronic Sinusitis

Understand

Overview

Chronic rhinosinusitis (chronic inflammation of the nasal and sinus mucosa, CRS) is an inflammatory condition of the nasal and paranasal sinus mucosa that — unlike the far more common acute form linked to a typical viral infection — is defined primarily by how long symptoms last. According to current European guidelines (EPOS 2020), chronic rhinosinusitis is diagnosed when at least two of four characteristic symptoms (nasal obstruction or congestion, nasal discharge or postnasal drip, facial pain or pressure, reduced or lost sense of smell) persist continuously for at least 12 weeks — not based on how intense the symptoms are at any given moment, which can actually be quite variable and episodic over time.

This time-based distinction has real clinical significance, because chronic sinusitis is a process with a fundamentally different, far more complex pathophysiology than a viral or bacterial acute infection — it isn't simply "an infection that didn't heal," but a distinct, chronic inflammatory state of the mucosa in which bacterial infection, if present, is usually a secondary rather than primary element of the disease. The EPOS 2020 guidelines further divide chronic sinusitis into forms with and without nasal polyps — a distinction that matters because these two forms differ in their inflammatory profile (type 2, eosinophilic inflammation usually dominates the form with polyps, versus a mixed profile in the form without polyps) and, consequently, in their response to treatment.

The factors contributing to the development and persistence of chronic sinusitis are multifactorial and partly overlapping. Nasal polyps — benign, stalked overgrowths of mucosa filling the nasal cavity and sinuses — are both a consequence and a perpetuating factor of chronic inflammation, mechanically impeding sinus drainage and airflow. Allergic rhinitis and asthma co-occur with chronic sinusitis more often than chance alone would suggest, pointing to a partly shared inflammatory basis (especially with type 2 inflammation) — patients with so-called aspirin-exacerbated respiratory disease (asthma, nasal polyps, and sensitivity to aspirin and other NSAIDs) represent a particularly difficult-to-treat subgroup. Structural factors, such as a deviated nasal septum or anatomical abnormalities of sinus openings, can impair natural mucus drainage and favor chronic stagnation of secretions. Increasing attention is also being given to the role of bacterial biofilms — organized, antibiotic-resistant bacterial structures settling on sinus mucosa, which may sustain local inflammation even without an acute, overt infection — though the exact role and frequency of biofilms in CRS pathogenesis remains an area of active research rather than a fully settled clinical fact.

The clinical picture, beyond the four main defining symptoms, often also includes chronic fatigue, headaches, sleep disturbance related to nasal obstruction, and, in a significant proportion of patients, a substantial reduction in quality of life comparable in some studies to the burden of other chronic diseases such as chronic heart failure — an often underappreciated aspect of this disease in its common perception as "just sinuses."

Diagnosis relies on the clinical picture meeting the time and symptom criteria, confirmed by nasal endoscopy (showing mucosal edema, discharge, or polyps) or paranasal sinus CT, which allows assessment of the extent of inflammatory changes and planning of any surgical treatment. It's worth noting that a plain sinus X-ray has limited diagnostic value in this context and isn't a recommended first-choice test when chronic sinusitis is suspected.

Who might genuinely benefit from this knowledge? Primarily people who've struggled for many weeks or months with nasal congestion, postnasal drip, or loss of smell and wonder whether it's "just a prolonged cold" or something warranting separate diagnosis. It's also useful for people with co-existing asthma or allergic rhinitis, in whom the risk of chronic sinusitis is elevated, and for those already diagnosed who wonder why yet another antibiotic doesn't bring lasting relief — in the chronic form of the disease, antibiotic therapy alone is rarely a sufficient, stand-alone solution.